TNOs are cool: a survey of the trans-Neptunian region: II. The thermal lightcurve of (136108) Haumea

Lellouch, E. and Kiss, C. and Santos-Sanz, P. and Muller, T. G. and Fornasier, S. and Groussin, O. and Lacerda, P. and Ortiz, J. L. and Thirouin, A. and Delsanti, A. and Duffard, R. and Harris, A. W. and Henry, F. and Lim, T. and Moreno, R. and Mommert, M. and Mueller, M. and Protopapa, S. and Stansberry, J. and Trilling, D. and Vilenius, E. and Barucci, A. and Crovisier, J. and Doressoundiram, A. and Dotto, E. and Gutierrez, P. J. and Hainaut, O. and Hartogh, P. and Hestroffer, D. J. and Horner, J. and Jorda, L. and Kidger, M. and Lara, L. and Rengel, M. and Swinyard, B. and Thomas, N. (2010) TNOs are cool: a survey of the trans-Neptunian region: II. The thermal lightcurve of (136108) Haumea. Astronomy and Astrophysics, 518 (3). L147. ISSN 0004-6361

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Abstract

Thermal emission from Kuiper belt object (136108) Haumea was measured with Herschel-PACS at 100 μm and 160 μm for almost a full rotation period. Observations clearly indicate a 100 μm thermal lightcurve with an amplitude of a factor of ~2, which is positively correlated with the optical lightcurve. This confirms that both are primarily due to shape effects. A 160 μm lightcurve is marginally detected. Radiometric fits of the mean Herschel- and Spitzer- fluxes indicate an equivalent diameter D ~ 1300 km and a geometric albedo pv ~ 0.70-0.75. These values agree with inferences from the optical lightcurve, supporting the hydrostatic equilibrium hypothesis. The large amplitude of the 100 μm lightcurve suggests that the object has a high projected a/b axis ratio (~1.3) and a low thermal inertia as well as possible variable infrared beaming. This may point to fine regolith on the surface, with a lunar-type photometric behavior. The quality of the thermal data is not sufficient to clearly detect the effects of a surface dark spot.
Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: © ESO, 2010. This publication is copyright. It may be reproduced in whole or in part for the purposes of study, research, or review, but is subject to the inclusion of an acknowledgment of the source.
Faculty / Department / School: Historic - Faculty of Engineering and Surveying - No Department
Date Deposited: 23 Jul 2014 04:53
Last Modified: 19 Apr 2016 02:41
Uncontrolled Keywords: Kuiper belt objects; 136108; Haumea; photometric techniques
Fields of Research : 02 Physical Sciences > 0201 Astronomical and Space Sciences > 020108 Planetary Science (excl. Extraterrestrial Geology)
02 Physical Sciences > 0201 Astronomical and Space Sciences > 020102 Astronomical and Space Instrumentation
02 Physical Sciences > 0201 Astronomical and Space Sciences > 020104 Galactic Astronomy
Socio-Economic Objective: E Expanding Knowledge > 97 Expanding Knowledge > 970102 Expanding Knowledge in the Physical Sciences
Identification Number or DOI: 10.1051/0004-6361/201014648
URI: http://eprints.usq.edu.au/id/eprint/25558

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